Engineers have developed glasses with liquid-based lenses that adjust its focus based on whatever the wearer is viewing.

The adjustable ‘smart glasses’, developed by a University of Utah team, incorporates an array of electrical, mechanical, optical, sensor, and computer technologies that work together seamlessly to offer a one-size-fits-all approach to vision correction,. The glasses are designed to mimic the behavior of the eye's natural lens — flexing to focus on wherever an individual is looking: near, far or in-between.

Unfortunately for many of us, as we age our lenses become stiffer and lose the ability to bend enough to focus at different distances. This is usually corrected by the use of standard glasses. And, in the case of those who are unable to focus at multiple distances, glasses with multiple lenses, such as bifocal, trifocal or progressive lenses are prescribed. However, these glasses have to be regularly replaced as our eyesight changes.

The newly developed ‘liquid lenses’ are made of glycerin, a thick liquid, sandwiched between flexible membranes. An electromechanical system in the frame of the eyeglass causes the membranes to bend, adjusting their focus and acting like multiple lenses.

The glasses are designed to work for most people at a wide range of distances due to a sophisticated computer algorithm that works with two critical variables. One is the eyeglass prescription that the user enters into the system using an attached mobile app. The other is where the user is looking — specifically how far away. This information is provided by a sensor mounted in the bridge of the glasses that uses pulses of infrared light to identify where the user is looking and provide the precise distance.

The combination of the user's prescription information and the distance information is used by the algorithm to instantly adjust the shape of the liquid lenses to allow the user to focus on what they are viewing. Remarkably, if the user looks elsewhere, the change in lens shape needed to focus at the new distance is made in a staggering 14 milliseconds — 25 times faster than an eye blink. Theoretically, these would be the only glasses a person would ever have to buy because they can correct the majority of focusing problems, with users having to only input their new prescription as their eyesight changes.

Because they contain a lot of technology, including a rechargeable battery, the current prototype is on the bulky side. However, a startup company, Sharpeyes, has been created to move toward commercialization with the aim of making thinner glasses available on the market in about three years.